dartfmt commandline argument tweaks.

pkg/analyzer/bin/formatter.dart

 #!/usr/bin/env dart
 
 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 import 'dart:convert';
 import 'dart:io';
 
 import 'package:args/args.dart';
@@ skipping 117 matching lines @@
 
 /// Initialize the arg parser instance.
 ArgParser _initArgParser() {
   // NOTE: these flags are placeholders only!
   var parser = new ArgParser();
   parser.addFlag('write', abbr: 'w', negatable: false,
       help: 'Write reformatted sources to files (overwriting contents).  '
             'Do not print reformatted sources to standard output.');
   parser.addOption('kind', abbr: 'k', defaultsTo: 'cu',
       help: 'Specify source snippet kind ("stmt" or "cu")'
-            ' --- [PROVISIONAL API].');
+            ' --- [PROVISIONAL API].', hide: true);
   parser.addFlag('machine', abbr: 'm', negatable: false,
       help: 'Produce output in a format suitable for parsing.');
   parser.addOption('selection', abbr: 's',
       help: 'Specify selection information as an offset,length pair '
-            '(e.g., -s "0,4").');
+            '(e.g., -s "0,4").', hide: true);
   parser.addFlag('transform', abbr: 't', negatable: true,
       help: 'Perform code transformations.');
   parser.addFlag('help', abbr: 'h', negatable: false,
       help: 'Print this usage information.');
   return parser;
 }
 
 
 /// Displays usage information.
 _printUsage() {
   var buffer = new StringBuffer();
   buffer..write('$BINARY_NAME formats Dart programs.')
         ..write('\n\n')
         ..write('Without an explicit path, $BINARY_NAME processes the standard '
                 'input.  Given a file, it operates on that file; given a '
                 'directory, it operates on all .dart files in that directory, '
                 'recursively. (Files starting with a period are ignored.) By '
                 'default, $BINARY_NAME prints the reformatted sources to '
                 'standard output.')
         ..write('\n\n')
-        ..write('Supported flags are:')
         ..write('Usage: $BINARY_NAME [flags] [path...]\n\n')
+        ..write('Supported flags are:\n')
         ..write('${argParser.getUsage()}\n\n');
   _log(buffer.toString());
 }
 
 /// Format this [src], treating it as the given snippet [kind].
 String _format(src, kind) {
   var formatResult = new CodeFormatter(formatterSettings).format(
       kind, src, selection: selection);
   if (machineFormat) {
     if (formatResult.selection == null) {
@@ skipping 11 matching lines @@
                      'offset': formatResult.selection.offset,
                      'length': formatResult.selection.length
                   }
     });
 
 /// Log the given [msg].
 _log(String msg) {
   //TODO(pquitslund): add proper log support
   print(msg);
 }